USE OF SEM-EDX FOR CHEMICAL ANCHORING CHARACTERIZATION OF POLYPROPYLENE ONTO GLASSFIBERS

MARIANA ETCHEVERRY; MARÍA LUJÁN FERREIRA; SILVIA E. BARBOSA; MARÍA JULIA YAÑES

ROSARIO, ARGENTINA

Congreso; 10th Inter-American Congress of Electron Microscopy 2009; 2009

Interamerican Committee of Societies for Electron Microscopy

The adhesion between matrix and fibers is an essential factor in determining the performance of thermoplastic-based polymer composite materials. In this way, several work and years were spent by researchers. However, the interfacial adhesion between polypropylene (PP) and glass fibers (GF) could be highly improved by chemical anchoring between PP and GF. In our group, metallocenic polymerization of PP from active sites on GF is proposed with very good results. The experimental route involves an initial contact with methylaluminoxane (MAO) and hydroxy-a-olefin to generate the anchorage points on the fiber surface, followed by a propylene polymerization catalyzed by EtInd2ZrCl2 (metallocene)/MAO. In order to assess the chemical bonding between PP and GF, the scanning electron microscopy with X-ray energy dispersive analysis (SEM-EDX) was used. The combination of this techniques give a very valuable tool to relate and analyze morphology and elemental chemical composition of the interphase, because of it allows the characterization of the elements involved in an micro area directly observed by SEM. In this work, a systematic experimental study of the interface using SEM/EDX is presented. GF were subject to the in-situ polymerization. After polymerization, some samples were etched with n-heptane at high temperature for extracting the polymer "physically" bonded to GF. At this condition it was proved that the entire polymer dissolves into the solvent. Then, if polymer remains onto fibers is chemically bonded. Then, three kinds of samples were analyzed; pure GF, polymerized GF and n-heptane etched polymerized GF, in a JEOL 35 CF equipped with secondary electron detection and X-ray energy dispersive system EDAX DX-4. All samples were previously coated with Au in a sputter coated to make them conductive.